The Glacial History of Michigan
Science Foundations 1
The Glacial History of Michigan
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The landforms of
Michigan are a result
of major changes
brought about by
continental glaciation.
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Landforms can be
depositional or
erosional in nature.
The Glacial History of Michigan
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Glacial landforms dominate the surface of the
whole state except the western half of the U.P.,
where eroded remnants of some of the oldest
mountains on earth are found.
There is considerable diversity in MI—from
glacial lake plains near Detroit, to sand dunes
bordering Lake Michigan, to massive moraines in
the northern lower peninsula.
The slope and soil variations associated with the
landforms are major factors in the agriculture,
economy and population density in various parts
of Michigan.
The Glacial History of Michigan

The last ice age occurred during the
Pleistocene Epoch (a division of time).
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It began 2 million years ago and ended
approximately 12,000 years ago.

We live in the Recent Epoch today (12,000
years ago to the present).
The Glacial History of Michigan
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The last ice age was
the fourth major ice
age in Earth’s 4.6
billion year history.
In addition to the
northern U.S. and
Canada, the last ice
age created the glacial
landforms of northern
Europe and Siberia.
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Others occurred:
– 2.0 billion years ago
– 600 million years ago
– 250 million years ago
(on Pangaea!)
The Glacial History of Michigan

During an ice age, it is not cold all the time.
Long periods of cold temperatures and
glaciation are broken up by equally long
periods of warm temperatures during which
glaciers recede and sea level rises.
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The warm periods are called interglacials,
meaning “in between times of glaciers.”
The Glacial History of Michigan

Look at the graph in
your packet and
observe the changes in
temperature during the
Pleistocene Epoch.

Focus on the names of
the glacial and
interglacial Periods.
ANSWER THE FOLLOWING:
*How many glacial periods
were there?
*About how often did they
occur?
*According to the graph, what
is global temperature doing now?
*Is the last Ice Age over yet?
Explain.
The Glacial History of Michigan
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There were 4 periods
of glaciation:
Nebraskan, Kansan,
Illinoisan, & the
Wisconsinan (which
created the landforms
seen in the Great
Lakes region).
See the diagram in the
packet.
The Glacial History of Michigan
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During a glacial
period, snow fall
accumulated into
layers of ice in 4
regions of North
America.
Label and color the
map in your packet
according to the
directions on the
diagram.
Greenland
Alpine
Keewatin
Labrador
ICE SPREADING CENTERS
The Glacial History of Michigan
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These huge masses of
ice were up to 10,000
feet or more in
thickness.
They moved south
into the U.S. leveling
existing hills, filled in
valleys, blocked
drainage patterns of
rivers, and gouged out
major basins.
The Glacial History of Michigan

The Great Lakes were carved out from river
valleys over the entire Pleistocene Epoch.

See the diagram in your packet.
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With each advance of the ice, they got
wider & deeper.
The Glacial History of Michigan
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The depth of the lake
is determined by the
thickness of the ice at
the time of glaciation.
The farther north the
lobe of ice, the thicker
it was.
Consequently, the
lakes get more shallow
in the southern Great
Lakes region.
LAKE:
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GREATEST DEPTH:
Superior =
Michigan =
Huron =
Ontario =
Erie =
1,333 ft.
925 ft.
725 ft.
283 ft.
212 ft.
The Glacial History of Michigan

The Great Lakes are 5
of the lakes in a 5,000mile long string of
lakes through central
and western Canada.

Each was carved by
huge continental ice
sheets over the last 2
million years.
The Glacial History of Michigan
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The moving ice carried sediments (small pieces of
rock) long distances. Rocks from Canada have
been found in Ohio and Indiana.
As the ice melted, the sediments were deposited,
creating huge landforms.
Some sediments were deposited in large ridges
and hills while others were carried away by vast
amounts of meltwater streaming from the melting
ice sheets.
See the diagrams in the packet for more details.
The Glacial History of Michigan
Another major result of glaciation was the
creation of a large number of inland lakes
and wetlands.
 More than 11,000 inland lakes are largely
the result of water accumulating in
depressions left by passing glaciers.
 Much of the swamp land of Michigan was
drained for agriculture. This accounted for
the loss of 50% of Michigan’s wetlands.
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The Glacial History of Michigan
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The flattest areas of southeast Michigan are
plains that are the result of deposits on the
bottom of ancient lakes.
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Detroit and the northwest suburbs used to
be under an ancient lake!
The Glacial History of Michigan
The last diagram shows the movement of
the ice over Michigan during the last glacial
period.
 This advance created the landforms and
features seen today.
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